This invention relates generally to a system for teaching students and health care professionals to perform medical examinations. More particularly, it relates to a system for teaching medical examinations performed manually inside a body cavity or anatomical space.
One of the most difficult examinations that students learn to perform in the first years of medical school is the female pelvic examination. The exam is generally taught through textbook reading, lectures, and observation of experienced physicians performing the exam. While these techniques contribute to the student""s overall knowledge, they do not provide the hands-on learning essential for development of proper technique.
Both live patients and manikins can provide the necessary hands-on learning. Live patients willing to be practiced on by inexperienced students, however, are in short supply. When available, this self-selected group does not necessarily provide a good baseline for teaching exams on healthy patients. Low-income women without access to regular medical care are often motivated to volunteer by financial incentive or incipient health problems. Other volunteers, including paid models, feel a duty to teach the students proper technique and can be quite assertive, further diminishing the student""s already fragile confidence in his or her examination procedure. The use of paid models can also be very expensive, and not all medical schools can afford this luxury. Another problem is the limited amount of time that the paid models are available.
To eliminate these potentially stressful problems and limitations, manufacturers have developed anatomical simulators or manikins to provide uniform environments in which the student can practice the exam as frequently as desired. One such gynecological simulator, known as ZOE(trademark), is disclosed in U.S. Pat. No. 5,472,345 to Eggert. While ZOE(trademark) is an excellent model of a human female pelvis, it presents a few problems for the instructor. The hands of the person performing the exam on the simulator are not visible to an observer; a student watching an instructor does not obtain a clear picture of basic internal exam technique, nor is an instructor able to accurately judge a student""s performance. Even with a cut-away or transparent region or suitable internal lighting, the simulator cannot significantly overcome the problem of limited visibility. Without detailed feedback, the student may not learn the essential elements of the exam or may develop improper technique. Unfortunately, the prevailing attitude in medical schools is that this type of manual exam is eventually learned through experience, and educators tend to tolerate the above problems.
In the last few decades, educators in many fields have used new technology to better implement proven educational methods. Medicine has, in general, been slow to implement new educational practices or technologies.
One area which has incorporated computerized techniques to improve the training process is life support. Systems have been developed for teaching medical procedures to students using manikins or other simulators containing sensors interfaced with computers containing teaching modules. U.S. Pat. Nos. 4,360,345 to Hon and 5,853,292 to Eggert et al. disclose two such systems for teaching cardiopulmonary resuscitation (CPR) and other basic physiological procedures. One important goal of these systems is to eliminate the need for instructors, thereby increasing the availability and decreasing the cost of training. In addition, these systems aim to provide realistic models for human patients and for expensive equipment. In general, they provide feedback similar to what can be provided by an instructor, experienced practitioner, or standard manikins and instruments. For all of the techniques taught, such as manual chest compressions, an instructor has access to the student""s hands, and can therefore provide the same feedback as the sensors. Specifically, the systems do not provide information on exams performed manually inside body cavities, for which there is currently no means for assessing exam performance.
Systems are also available for simulating minimally invasive surgical procedures. In this field, as opposed to classical surgery with its large incisions, full anesthesia, and long hospitalizations, an instrument is inserted into a small incision made in the patient. A surgeon conducts a procedure using tactile feedback imparted through the instrument combined with real-time visual display images of the patient""s internal landscape. Teaching systems for these surgical techniques focus on a virtual instrument interfaced with a computer system containing real image data. Some examples are disclosed in U.S. Pat. Nos. 4,907,973, issued to Hon, 5,800,179, issued to Bailey, and 5,800,177, 5,800,178, and 5,822,206, all issued to Gillio. The virtual instrument is inserted into an orifice, and movement of the instrument produces an image and other feedback on a display monitor. By varying the image data, many different types of operations can be practiced. These systems are highly specialized to minimally invasive surgery. Anatomical accuracy is provided by the image data, not by the orifice or access sites, and they are not applicable for teaching manually performed exams or palpation techniques.
There is a need, therefore, for a system for training students to perform pelvic and other internal exams, of which a key measure of success is the tactile contact provided by the student.
Accordingly, it is a primary object of the present invention to provide a training system that provides immediate feedback to students performing a medical exam manually inside a body cavity, for example, a pelvic or rectal exam. The system provides feedback that an instructor alone cannot give.
It is a further object of the invention to provide a teaching system that measures a student""s performance against an objective standard and provides a rating of the student""s performance.
It is an additional object of the invention to provide a system that simulates various environments in which an exam occurs, including an examination room or emergency room, and various types of patients, including a wide range of clinical conditions and demographics.
It is another object of the present invention to provide a system that interfaces with different feedback presentation units, some of which make the unit portable.
It is a further object of the present invention to provide a system that can be used for any type of medical examination performed manually within an anatomical space that is hidden from view.
Finally, it is an object of the present invention to provide a system that is economical to construct and easy to transport.
These objects and advantages are attained by a system for training a student to perform a medical exam performed manually inside a body cavity, part of whose inside surface is not visible to the student. An instructor cannot see what the student""s hands are doing inside the body cavity, and so the system provides feedback that allows both the student and instructor to immediately judge the student""s proficiency in performing the exam. The system has three main parts: an anatomical simulator with a simulator cavity, a tactile sensor in the anatomical simulator, and a feedback presentation unit in communication with the sensor. When manual contact is made with an inside surface of the simulator cavity, the sensor generates a signal in response. Performance of the exam inside the simulator cavity generates a set of signals from the sensor, which are used by the feedback presentation unit to provide feedback for the exam.
Any exams requiring palpation or manual assessment inside body cavities can be taught, such as pelvic exams, rectal exams, or surgical procedures including abdominal, pelvic, and thoracic (chest) surgery. The simulator and feedback are correlated with the exam; for example, the simulator is a manikin of the lower torso of a human female for teaching pelvic exams. The simulator and feedback are also adjustable to select one of a number of predetermined exams. Preferably, the simulator includes removable anatomical parts, for example, a cervix, uterus, and ovaries, and the surfaces of these parts make up a portion of the inside surface of the cavity. Some of the removable anatomical parts may represent a diseased condition; the exam is then correlated with the diseased or normal condition. The student learns which exam to perform by manually detecting which removable part is in the simulator. The sensor is preferably a force sensing resistor, and the signals generated by the sensor are representative of a force on the inside surface of the simulator cavity.
The type of feedback provided varies with the feedback presentation unit. The feedback may be an indication of completion of the exam, defined by a set of predetermined steps; a graphical display of the exam results; instruction to the student; or a rating of the exam. In a preferred embodiment, the feedback presentation unit is a computer with a processor, display means, and converting means for converting or transforming the signals from the sensors into inputs for the computer. Computer readable code executable by the processor instructs the computer to process the inputs to provide immediate feedback to the student. For example, the code instructs the computer to compare the inputs with a reference exam, which varies with the diseased or normal condition, to derive a rating for the performance. The computer can also include storage means for storing video signals and associated audio signals representing a realistic patient environment and correlated with the reference exam and removable parts used during the exam. The computer readable code controls presentation of the video and audio signals, in addition to processing of the inputs. In alternative embodiments, the feedback presentation unit is a liquid crystal display (LCD) or an analog display.
Also provided by the present invention is a method for training a student to perform an exam performed manually inside a cavity. The method is preferably implemented by a computer and has the following steps: receiving signals from a tactile sensor in a simulator cavity of an anatomical simulator; and providing immediate feedback to the student. Signals are generated in response to a manual contact of the student with an inside surface of the simulator cavity, and the feedback is in part derived from the signals. The feedback also depends on a predetermined exam type, such as a pelvic or rectal exam or surgical procedure, or variations of the exam type. Feedback includes a graphical display, a rating, or instruction to the student. The signals can be compared with a reference exam corresponding to a manually detectable and possibly pathological condition of the cavity to derive the feedback. The signals can also be analyzed to determine whether a set of predetermined steps has been completed by the student, which is indicated to the student in the feedback. Video and audio signals representing a realistic patient environment can be presented to the student.